160 



standing in the small "bays" of beech foliage and all with the faces directed to- 

 wards the moors from which the females steered their way into the swarm. 



From the middle of May the egg-laying processes go on ; as far as I know a little 

 later than the process begins for A. maculipennis. The larvae of the two species are easily 

 distinguished from each other by means of the clypeal hairs; in the larva of A. 

 bifurcatus the inner pair is simple, and the outer only cleft a few times; in A. ma- 

 culipennis the inner is cleft several times, the outer is a thick brush; moreover the 

 float hairs of A. bifurcatus have about sixteen leaflets, those of A. maculipennis 

 about twenty-two. Also in the comb of the two species there are great differences. 

 Moreover, as far as I know, the larva of A. maculipennis is always of a much 

 brighter colour, commonly green, whereas that of A. bifurcatus is darker. Further- 

 more it may be pointed out that most probably all fullgrown larvae of Anophelines 

 which are to be found in May-^-June mainly or only belong to A. maculipennis, 

 whereas all Anophelin larvae which occur from October and during the winter 

 months always only belong to A. bifurcatus. The two species meet each other as 

 larvse only in the month June September; during this time, as far as I know, A. 

 maculipennis everywhere preponderates over A. bifurcatus; in the six winter months 

 the opposite is the case, and in the true winter months we only find the larvae of 

 A. bifurcatus. As well known (GRASSI 1901 p. 53; LEVANDER 1902 p. 11) most of the 

 Anophelin-larvse are found in the thick green layers of algae on the surface of smaller 

 ponds (Cladophora, Oedogonium, Spirogyra); as far as I know especially near the coast. It 

 is very difficult to observe the larvae in Nature; but from my boat when lying in 

 the Potamogeton region of our ponds I have learned to see the larvae between the 

 Potamogeton leaves. The larvae are often found together but those of A. bifurcatus 

 preponderate in clear cold localities. 



It is a well known, often established, fact that whereas A. maculipennis hiber- 

 nates only as imago, A. bifurcatus hibernates as larva. See f. i. NUTTALL and SHIP- 

 LEY (1901 p. 452; 1902 p. 64); GALLI VALERIC and NARBEL (1901). In September I 

 have, especially in a little valley near Suserup, seen the swarms of males of A. 

 bifurcatus; then the females probably lay their eggs; at all events vast numbers of 

 small black Anophelin larvae occur; at that time these larvae appear almost 

 everywhere in small ponds rich in vegetation. Their home is the water rim, the 

 larvae lying, like the Dixa larvae, almost upon dry land; in this water rim the 

 females have deposited their eggs; these are rather difficult to see in Nature, 

 but if we take a piece of milky coloured glass or of white paper and bring it 

 under the surface, but as near this as possible, we shall see that the eggs are ex- 

 tremely common, further that the numerous black Anophelin larvae originate from 

 these eggs. The larvae now live in the water rim for more than two months, but 

 when the temperature of the water is about zero, they disappear and hide themselves 

 at the bottom of the ponds; at that time they have almost reached the fullgrown 

 size, the hibernation as far as I know always taking place in the last rarely in the 

 second larva stage. During winter the larvae do not grow, most probably they eat 



